Connection elements of this kind are especially employed in aircraft construction. Aircraft usually have a cabin chamber in which at regular intervals so called center regions are provided. In these center regions there are provided kitchens, among others with separate cooling aggregates. In order to be flexible with respect to the position of the individual aggregates within the center region for creating so called flex-zones, there are usually provided several connections at which the or each aggregate may be adapted. For supplying the aggregates with the necessary supply lines or offtake lines for the cooling medium or the like which are commonly situated below the bottom plate of the cabin in so called supply chambers, connection elements are necessary which secure the bottom feed-through, namely the connection between a conduit element in the supply chamber to a conduit element in the cabin chamber. As conduit elements, there are understood all tube elements, hose elements, tube-hose elements or connection elements of other kinds. Besides the conduits for supply and leading-out of, for example, cooling element in the cabin region, below the bottom plate in the supply chamber there are also further conduit elements, for example the main conduit for the air conditioner, as well as cross beams and other members.
The known connection elements have a tubular connection part which at least partly extends into the cabin chamber through the separation element. At the section of the connection part extending into the cabin chamber, at the outer side thereof is disposed a connection element corresponding to respective fastening element at the conduit element. Usually, the connection part is provided with an outer thread onto which the conduit element of the cabin chamber is screwed.
On the one hand, this has the disadvantage that a big structural shape is necessary, namely particularly a big installation height. Thereby, an installation above cross beams or main conduits for the air conditioner in the supply chamber is not possible. On the other hand, due to the excess length with respect to the bottom plate, the connection elements form an abutting edge, which presents a stumbling danger in the cabin chamber and complicates the mounting of a kitchen as well as the change of position of individual aggregates. Moreover, the known connection elements have a sealing difficulty. By means of the outer thread of the connection element, a sealing with respect to humidity is not secured between the cabin chamber and the supply chamber (upper deck or lower deck). A further disadvantage is that the known connection elements require a very big insection in the bottom plate, which makes necessary a strengthening of the surrounding bottom plate.